Whatever other parties might think any policy by Taiwan other than cooperation with China is suicide. IF DPP were to act irresponsibly it will be enough for China to declare its ports and airports on the island closed. Then any ships and aircraft using them will not be insured. Very few ship or aircraft owners will take the risk and the economy of the island will be strangled.The other factor is Taiwan. With the presidential election coming up next year with KMT facing a complete wipe out and DPP a guarantee win, there is a high possibility it could provoke a conflict and escalate into a full blown war.
That, after all, is the meaning of the One China policy of most countries in the World.